Friday, April 30, 2010

Children normally experience flights of fancy, including imaginary friends and conversations with stuffed animals, but some of them are also having hallucinations and delusions which might be the early signs of psychosis.

A study of British 12-year-olds that asked whether they had ever seen things or heard voices that weren't really there, and then asked careful follow-up questions, has found that nearly 6 percent may be showing at least one definite symptom of psychosis.

The children who exhibited these symptoms had many of the same risk factors that are known to correlate with adult schizophrenia, including genetic, social, neurodevelopmental, home-rearing and behavioral risks.

"We don't want to be unduly alarmist, but this is also not something to dismiss," said co-author Terrie Moffitt, the Knut Schmidt Nielsen professor of psychology and neuroscience and psychiatry & behavioral sciences at Duke University. The study appears in the April issue of Archives of General Psychiatry.

The children were participants in the long-term Environmental Risk Longitudinal Twin Study in Britain, which includes 2,232 children who have been tracked since age 5 and reassessed at 7, 10 and 12.

The British study is an outgrowth of research that the same group did earlier with a long-term cohort in Dunedin, New Zealand. At age 11, those children were asked about psychotic symptoms, but the researchers waited 15 years to see how, as adults, their symptoms matched what they reported at 11. By age 26, half of the people who self-reported symptoms at age 11 were found to be psychotic as adults.

"It looks like a non-trivial minority of children report these symptoms," said co-author Avshalom Caspi, the Edward M. Arnett professor of psychology and neuroscience and psychiatry & behavioral sciences at Duke.

The findings provide more clues to the development of schizophrenia, but don't solve any questions by themselves, said co-author Richard Keefe, director of the schizophrenia research group in the department of psychiatry and behavioral sciences at Duke.

Schizophrenia often goes undetected until adolescence, when the first overt symptoms -- antisocial behavior, self-harm, delusions -- begin to manifest in an obvious way. But nobody knows whether the disease is triggered by the process of adolescence itself, or brain development or hormone changes. "It's my impression that all of those things interact," Keefe said.

Psychotic symptoms in childhood also can be a marker of impaired developmental processes, and are something caregivers should look for, Moffitt said. "There is not much you can do except monitoring and surveillance," Moffitt said. "But we feel we should be alerting clinicians that there's a minority to pay attention to."

While the incidence of psychotic symptoms in this study was around 5 or 6 percent, the adult incidence of schizophrenia is believed to be about 1 percent, Keefe added. There are some recent findings however, that many more people experience hallucinations and delusions without being diagnosed as psychotic, he said.

The research was supported by the U.S. National Institutes of Health, UK Medical Research Council, The National Alliance of Research on Schizophrenia and Depression, the Health Research Board of Ireland and the William T. Grant Foundation.

Children with dyslexia often struggle with reading, writing and spelling, despite getting an appropriate education and demonstrating intellectual ability in other areas. New neurological research from Vanderbilt University has found that these children’s difficulties with written language may be linked to structural differences within an important information highway in the brain known to play a role in oral language.

The findings were published in the June 2010 issue of Cortex.

Vanderbilt researchers Sheryl Rimrodt and Laurie Cutting and colleagues at Johns Hopkins University and Kennedy Krieger Institute used an emerging MRI technique, called diffusion tensor imaging (DTI), to discover evidence linking dyslexia to structural differences in an important bundle of white matter in the left-hemisphere language network. White matter is made up of fibers that can be thought of as the wiring that allows communication between brain cells; the left-hemisphere language network is made up of bundles of these fibers and contains branches that extend from the back of the brain (including vision cells) to the front parts that are responsible for articulation and speech.

“When you are reading, you are essentially saying things out loud in your head,” Cutting said. “If you have decreased white matter integrity in this area, the front and back part of your brain are not talking to one another. This would affect reading, because you need both to act as a cohesive unit.”

Rimrodt and Cutting used the DTI technique to map the course of an important white matter bundle in this network and discovered that it ran through a frontal brain region known to be less well-organized in the dyslexic brain. They also found that fibers in that frontal part of the tract were oriented differently in dyslexia.

“Finding a convergence of MRI evidence that goes beyond identifying a region of the brain that differs in dyslexia to linking that to an identifiable structure and beginning to explore physical characteristics of the region is very exciting,” Rimrodt said. “It brings us a little bit closer to understanding how dyslexia happens.”

Rimrodt is assistant professor of developmental medicine. Cutting is Patricia and Rodes Hart Chair at Vanderbilt’s Peabody College of education and human development and an investigator in the Vanderbilt Kennedy Center for Research on Human Development. The researchers completed the work at the Kennedy Krieger Institute with their colleagues there before moving to Vanderbilt.

The research was funded by the Johns Hopkins School of Medicine General Clinical Research Center, the Kennedy Krieger Institute’s Learning Disability Research Center and F.M. Kirby Research Center for Functional Brain Imaging, the National Institute for Neurological Disorders and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.